How to enable openCL rendering in Blender 2.75 rc2
I have found solution to my problem. To enable openCl on Linux Mint 17.1 with ATI radeon video card just install ocl-icd-libopencl1 package for 64 bit system, or ocl-icd-libopencl1:i386 for 32 bit system. No need to run Blender as root or set up environment variable.